Stacking device for printing machines



Oct. 8, 1963 w. KOCH 3,106,393

STACKING DEVICE FOR PRINTING MACHINES Filed NOV. 8, 1961 3 Sheets-Sheet 1 Fig.1

In vemar: A/ER IVER KOCH Oct. 8, 1963 w. KOCH 3, 0 ,393

STACKING DEVICE FOR PRINTING MACHINES Filed Nov. 8, 1961 3 Sheets-Sheet 2 Fig.2

Jnventar: l/ER/VER Kacll HMO/M Oct. 8, 1963 'w. KOCH ,3

STACKING DEVICE FOR PRINTING MACHINES Filed Nov. 8, 1961 3 Sheets-Sheet 3 Jnventor: [/53 IVER KOCH HrraR IVE/5 United States Patent 3,106,393 STACKING DEVICE FOR PRINTING MACHINES Werner Koch, Oifenbach (Main), Germany, assignor to Roland ()ifsetmaschinenfabrik Faber & Schleicher AG., Offenbach (Main), Germany, a German body corporate Filed Nov. 8, 1961, Ser. No. 151,596 Claims priority, application Germany Nov. 19, 196i) 2 Claims. (Cl. 271-64) This invention relates to machines for printing on sheets and is particularly concerned with the stacking devices of such printing machines, in which the sheets, after printing, are deposited on stacks or piles tobe removed whenthe stack or pile has attained a certain predetermined height. The invention, in one of its aspects, has reference to'that type of stacking devices, in which two stacks are used and arranged to be served in the feeding direction of the sheets selectively either one stack continuously at a time, or alternately one after the other during the printing operation of the machine.

The known stacking devices of this type are generally provided with means which permit the lowering of the sheets onto either the one or the other stack, which hereinafter will be referred tons the first and the second stack, in a manner which will enable the sheets to be carried clear over the first stack when the second is to be served so as to prevent them from coming into contact with the top sheet of the'first stack and to thereby smudge the fresh printing thereon.

It is known, for this purpose to provide supporting bars in the form of a grate or rake on which to support the sheets when they are deposited on the second stack and by which they are carried over the first stack. These grates or rakes are capable of swinging movement about an axis which extends transversely to the feeding direction of the sheets, so that in one of theirend positions they are above, and in their other end position below the path of the sheets as determined by the chain grippers by which the sheets are advanced. In the first case the sheets can be lowered directly onto the first stack, while in the second case the sheets are deposited on the second stack whereby the bars of the grate serve as a support for the sheets while they pass through the space above the first stack and keep them out of touch therewith.

A disadvantage of this known arrangement is that the bars of the grate must be of a considerable length, par-- ticularly when they are used in large sheet printing machines. They are supportedon their vgrates at only one of their ends and must 'be swung very quicklyfrom one end position into the other, which causes them to vibrate and thereby endanger the correct positioning of the sheets. During the full operation speed of the machine, particularly when the sheets are to be deposited on the two stacks alternately as the bars are raised and lowered in the cycle of operations, these vibrations become so intense, that the free ends of. the bars get into the path of the sheets and very often tear them out of the hold of their grippers.

It is, therefore, one object of the invention to remove these disadvantages -by avoiding the transverse movement of the bars and to make the same capable of movement in a plane substantially parallel to the plane of the sheets only, so that no vibrations will be able to occur.

Another object of the invention is to make the bars shorter and, thereby, the grate sturdier and more stable in action.

Still another object is to so subdivide the grate into independently operating sections or units, preferably two, so as to enable a'better accommodation in the overhang of the stacking device without having to increase the length of the same. e i

. stack.

ICC

Yet a further object of the invention rests in the provision of means by which the movement of each unit of the grate can be adapted, within the cycle of operations of the machine, to the movement of the sheets over the first stack, so that the forces of acceleration which are set up in the driving means, will be reduced to a minimum. It will not be necessary for the individual units of the grate to be in the working position above the stack until the front edge of a sheet approaches the space over the first stack. Thus it is not necessary for the two units of the grate to move in synchronism. Besides, owing to the movement of the units in a plane parallel to the stack surface, cross forces and, incidentally, any vibrations are practically avoided.

Still another object of the invention is the provision of auxiliary gripping means at the first stack which can be rendered inoperative when the sheets are to be deposited on the second stack.

The space gained by the new arrangement of the supporting grate in accordance with the invention can be used for the accommodation of an auxiliary gripper arrangement which ensures an orderly positioning of the sheets on the first stack.

Furthermore, the auxiliary grippers in accordance with the invention are connected to a control mechanism for the selection of the stack to be served and, incidentally, of the movement of the sheet supporting grate member, so that it only comes into action when the sheets are to be deposited on the first stack.

In order to press the sheets onto the first stack a blower or the like may be provided which is set inoperative when the sheets are to be placed onto the second stack. The invention thus provides that the controls for the movement of the sheet supporting grate can, at the same time,

be utilized for the control of the blowing means.

With these and other objects in view the invention mainly consists in the provision, in a stacking device for sheet printing machines operating with two stacks, of a sheet supporting grate or the like which is composed of two independent sections or units, which are movable in mutually opposite directions in a plane parallel to the stack surfiaces, and in means for controlling the movement of the two sections so as to automatically position the sheets selectively on either the one or the other stack in sequent-al succession, or alternately on both, and in the further provision of an auxiliary gripper in cooperation with the first stack and the grate section therefor, and in means for rendering the said auxiliary gripper inoperative when the sheets are being deposited on the second The accompanying drawings illustrate a stacking device in accordance with the invention largely diagrammatic by way of example. In these drawings,

FIG. 1 is a side elevation of the stacking device in operation on the second stack,

FIG. 2 is a similar side elevation of the device in operation on the first stack, while FIG. 3 is a plan view of FIG. 1.

As shown in these drawings, the sheets are taken from the grippers of the chain conveyor '1 in substantially known manner as they are being delivered by the printing machine and supplied to receiving areas to form stacks 2 and 3. The printing machine itself is not illustrated as it may be of any known or convenient type, and the conveyer chains are passed over sprockets 4, 5 and 46, 50 respectively, in the side walls 6, 7 of the overhanging stacking device. Provided above the first stack 2 in the traveling direction of the sheets is a supporting device for the sheets which come into use when the sheets are to be deposited on the second stack 3. This supporting device consists of two parts or sections of which each is composed of a plurality of bars 8 and 9. The bars 8 are attached at one of their ends to a slide or carriage which is formed by a cross member 10 and two longitudinally directed side members 11 and 12, which are adapted to move on guide rails 13 and 14 respectively (FIG. 3). Similarly arranged are the bars 9 on a slide or carriage which consists of a cross bar 15 and longitudinally directed side members 16 and 17 adapted to run on guide rails 18 and 19. All these guide rails 13, 14- and 18, 19 are fitted to the inside Walls 6 and 7 of the stacking device as by means of angle irons 20. The arrangement is such that when the bars 8 and it are movable With their carriages, they will move in mu-tuall opposite directions. FIG. 1 shows them in their operating position in which they form a practically continuous grate, while in FIG. 2 they are shown apart from each other. It will be seen from these figures that in the first case the sheets are deposited on the second stack 3 as indicated by the arrow a, and in the second case on the stack 2 as shown by the arrow b.

The side members 12 and 17 of the carriages are provided with racks (FIG. 3) which are in engagement with pinions 21 and 22 respectively. Fitted to the outwardly extending shafts of these pinions are other pinions 23 and 24-, which are connected to them each by means of an electro-magnetic clutch built into the pinions 21 and 23. In engagement with the pinions 23 and 24 are toothed segments 25 and 26 which are oscillated by connecting rods 27 and 28 from cranks 29 and 30 respectively. Rotation to these cranks is imparted by the conveyer chain '1 via the sprockets 5 and the gear wheels 31 and 32, it being understood that instead of the crank drive a cam drive or any other driving means may be provided. The entire control mechanism for the gear Wheels 21 and 22 is preferably housed in a gear case 33 (FIG. 3), as is also a control hand lever 34 capable of three different positions which are indicated by 34, middle, 34', left, and 34", right.

The auxiliary gripper device 35 is actuated by the connecting rods 61, 62 and the bell crank levers 63, 64-, which are pivoted to the inside of the side wall 6 of the machine frame, by the draw bars 65, 66 and the follower levers 67, 68 of the earns 69 and 70. These cams are connected to the sprocket 4 by means of an electro-magnetic clutch which is built into the body of the sprocket. The auxiliary gripper device 36 is actuated by the cams 7d and 72 (FIG. 3) which can be connected to the same by means of an electro-magnetic clutch inside the sprocket 4%.

A multiple change-over switch can be actuated by the aforesaid hand lever 34 over which the conduits of all electro-magnetic clutches are passed and which provides that, when the hand lever 34 is in its middle position, the sheets will be delivered to the stacks 2 and '3 alternately. In this case the clutches between the pinions 2E, 23 and 22, 24 respectively are in constant engagement and the bars 8 and 9 are moved in conformity with the cycle of operations of the printing machine into the positions of FIGS. 1 and 2 alternately. The auxiliary grippers 35 and 36 are also actuated alternately each during the corresponding second cycles of the machine when a sheet is deposited on the respective stack.

The cranks 29 and 30 are positioned at a predetermined angle with respect to each other, which angle, however, is adjustable so that the movement of the bars 3 and S over the rack 2 can always be suited to the movement of the sheets over the stack 2. The position 34 of the control hand lever 34, for instance, may be such that all sheets will be deposited on stack 3. In this case the bars 8 and 9 remain in their working positions as shown in FIG. 1 after the clutches between the Wheels 21, 23 and 22, 24 respectively have become disengaged. The auxiliary gripper 35 then is at rest, while the auxiliary gripper 36 is being actuated during every cycle of the machine. In the right position 34" of the control lever all sheets will be deposited, for instance, on stack 2 and the operation of the parts 3, 9, 35 and 36 takes place in the reversed sense to the one just described.

What I claim is:

1. In a sheet-printing machine, a stacking device for stacking the sheets in two independent stacks arranged one after the other in the direction of feed, such device comprising means over the first stack for temporarily screening the sheets against contact with the said first stack, said means comprising two mutually independent support units, each support unit comprising a carriage, guide rails for the said carriage, bars fitted to the said carriages extending in mutually opposite directions for engaging moving sheets as the latter travel over the first stack, a rack on each of the said carriages, a pinion in engagement with each of the said racks, a gear wheel in cooperation with each of said pinions, a clutch between the said pinions and said gear wheels, and geared means for rotating said gear Wheels in mutually opposite directions for moving the said support units in likewise opposite directions in a plane substantially parallel to the path of travel of said sheets over said stacks.

2. A stacking device for sheets fed from a sheetprinting machine, said device comprising means defining a first and a second sheet-receiving area aligned in the direction of feed of the sheets, shielding means temporarily shielding moving sheets against contact with stacked sheets in the first receiving area as said moving sheets travel over the first receiving area toward the second receiving area, said shielding means including two support units, each of which has a first operative position wherein at least a portion of each of said support units overlies the first receiving area to prevent the aforesaid contact between said moving and stacked sheets and a second operative position wherein each of said support units is displaced from said first operative position to allow sheets to be received in said first receiving area, an actuating means connected to each of said support units for operating said support units between said operative positions by moving each of said support units parallel to the path of movement of said moving sheets above said receiving areas, a blowing means cooperating with sheets stacked in the first receiving area for pneumatically pressing sheets onto the stack in said area, and means for rendering said blowing means inoperative when sheets are to be deposited in the second receiving area.

References Cited in the file of this patent UNITED STATES PATENTS 2,125,467 Sinclair Aug. 2, 1938 2,205,767 Lamb June 25, 1940 2,488,674 Malott Nov. 22, 1949 2,673,735 Niles et al Mar. 30, 1954 2,950,108 Golding Aug. 23, 1960 

1. IN A SHEET-PRINTING MACHINE, A STACKING DEVICE FOR STACKING THE SHEETS IN TWO INDEPENDENT STACKS ARRANGED ONE AFTER THE OTHER IN THE DIRECTION OF FEED, SUCH DEVICE COMPRISING MEANS OVER THE FIRST STACK FOR TEMPORARILY SCREENING THE SHEETS AGAINST CONTACT WITH THE SAID FIRST STACK, SAID MEANS COMPRISING TWO MUTUALLY INDEPENDENT SUPPORT UNITS, EACH SUPPORT UNIT COMPRISING A CARRIAGE, GUIDE RAILS FOR THE SAID CARRIAGE, BARS FITTED TO THE SAID CARRIAGE EXTENDING IN MUTUALLY OPPOSITE DIRECTIONS FOR ENGAGING MOVING SHEETS AS THE LATTER TRAVEL OVER THE FIRST STACK, A RACK ON EACH OF THE SAID CARRIAGES, A PINION IN ENGAGEMENT WITH EACH OF THE SAID RACKS, A GEAR WHEEL IN COOPERATION WITH EACH OF SAID PINIONS, A CLUTCH BETWEEN THE SAID PINIONS AND SAID GEAR WHEELS, AND GEARED MEANS FOR ROTATING SAID GEAR WHEELS IN MUTUALLY OPPOSITE DIRECTIONS FOR MOVING THE SAID SUPPORT UNITS IN LIKEWISE OPPOSITE DIRECTIONS IN A PLANE SUBSTANTIALLY PARALLEL TO THE PATH OF TRAVEL OF SAID SHEETS OVER SAID STACKS. 